Tutorial 2: EXPLORE by variable

Preparing for climate change when planning or management is focused on a specific issue can involve asking the question: For the Pacific Northwest, where could changes occur first because of climate change?


I am an air quality specialist concerned about ozone.  The anticipated warmer temperatures could promote ozone formation, increasing the number of ozone nonattainment areas.  I wonder if climate change could change the current ozone attainment/nonattainment and maintenance status of some areas in the Pacific Northwest, and where could these changes occur?

Variable of interest

First I need to identify the variables in the tool that will help answer my question. The Time of Emergence tool provides results for 35 types of variables (158 specific variables) listed in the Read section under Climate Variables. I can use the following variable as a proxy for ozone since daily maximum temperature exceeding 90°F (32.2°C) implies more favorable conditions and increased risk for ozone formation:

         Number of days with daily maximum temperature above 90°F, annual

Using the Time of Emergence tool

To answer my question -- Where could climate change first start having a significant impact on ozone attainment in the Pacific Northwest? -- I need to enter the tool pathway designed to depict spatial patterns of change across the region, choose the specific variable I'd like to explore and select analytical parameters (assumptions) that fit my risk tolerance.

Initiate the variable-based query:

  • Go to EXPLORE.
  • Select I want to focus on where changes could occur first (across the region). Click Next.

Choose specific variable of your interest:

  • To simplify the list of available variables for ease of selection, (1) Filter variables (optional) by selecting Air Temperature (Theme), Extreme (Type), and Annual (Season). (Optional)
  • To choose your specific variable of interest, under (2) Select one or more variables, select Number of days with daily maximum temperature above 90°F, annual.

  •  To see the spatial changes in the variable, under Choose map type, select Emergence location.
  •  To see the whole Pacific Northwest region, under Choose domain of interest, select Pacific Northwest. Click Next.

Select analytical parameters (assumptions) that fit my risk tolerance:

  • I am interested in seeing where the earliest emergence of changes in Number of days with daily maximum temperature above 90°F might occur, so I am going to select input parameters associated with earlier emergence: highemission scenario and high management sensitivity to changes in conditions. I am interested in viewing results from the most recent statisically-downscaled dataset so I choose BCSD5; for ease of viewing I choose the state boundary overlay. Under Refine Map Query, I select the following choices and request the map:

High Management Sensitivity (this results in earlier emergence than for low management sensitivity, because of a lower threshold for the amount of change that would trigger impacts of concern)

High Emission Scenario (this results in earlier emergence than for the low emissions scenario, due to greater atmospheric concentrations of greenhouse gases, aerosols etc.)

State (Overlaid Boundaries)

BCSD5 (statistically-downscaled) Climate Dataset

Time of Emergence Query Results

After submitting these selections, a database query returns a visualization of the relevant results.

The animated series of maps shows that much of the Pacific Northwest (except the coastal areas and parts of eastern Washington) are projected to deviate significantly from the baseline conditions (1950–1999), given a moderate rate of climate change, and the specified scenarios and climate data source.

The shaded areas indicate locations where 60% or more of the global climate models examined simulate increasing Number of days with daily maximum temperature above 90°F.

The different shadings indicate the level of agreement among the global climate models examined that emergence has occurred by the time indicated in the legend (2025, 2050, 2075, 2100)

If I want to see how different choices about emission scenarios, management sensitivity, or climate dataset affect the estimated time of emergence, I can change those input assumptions and rerun the query.

Compared to the results for BCSD5, the BCSD3 projections indicate a similar pattern of emergence in the Pacific Northwest. The BCSD3 dataset is higher resolution, so shows finer detail.


Continue Exploring



The Time of Emergence project was conceived and funded by U.S. Army Corps of Engineers Climate Preparedness & Resilience programs & U.S. Environmental Protection Agency-Region 10. Methodologies and stakeholder engagement were developed and implemented by the University of Washington's Climate Impacts Group. The Time of Emergence online tool was developed with support from the Center for Data Science, University of Washington-Tacoma.